Elevation of HDL cholesterol by 4-[(aminothioxomethyl)-hydrazono]-N-(substituted)-4-arylbutanamides

ABSTRACT

Compounds of this invention increase plasma levels of high density lipoprotein or HDL, the “good” cholesterol and as such may be useful for treating diseases such as atherosclerosis. These compounds are represented by the formula                    
     wherein: 
     R 1 , R 2 , and R 3  are independently hydrogen, C 1 -C 6  alkyl, phenyl or —(CH 2 ) 1-6  phenyl where phenyl is optionally substituted by halogen, cyano, nitro, C 1 -C 6  alkyl, C 1 -C 6 alkoxy, trifluoromethyl, C 1 -C 6  alkoxycarbonyl, —CO 2 H or OH; 
     R 4  and R 5  are independently hydrogen, C 1 -C 10  alkyl, C 3 -C 8  cycloalkyl, —(CH 2 ) 0-6 Ar 1  where Ar 1  is phenyl, naphthyl, furanyl, pyridinyl or thenyl and Ar 1  can be optionally substituted by halogen, cyano, nitro, C 1 -C 6  alkyl, phenyl, C 1 -C 6  alkoxy, phenoxy, trifluoromethyl, C 1 -C 6  alkoxycarbonyl, —CO 2 H or OH, or R 4  and R 5  together with the nitrogen to which R 4  and R 5  are attached form a ring containing 4-7 carbon atoms; 
     and Ar is phenyl, naphthyl, furanyl, pyridinyl or thienyl which may be optionally substituted by halogen, cyano, nitro, C 1 -C 6  alkyl, C 3 -C 6  cycloalkyl, phenyl, C 1 -C 6  alkoxy, phenoxy, trifluoromethyl, C 1 -C 6  alkoxycarbonyl, —CO 2 H or OH.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of Ser. No. 09/193,026 filed Nov. 16,1998 now, U.S. Pat. No. 6,316,467, which claims the benefit of U.S.Provisional Application No. 60/108,159, which was converted from U.S.patent application Ser. No. 08/972,119, filed Nov. 17, 1997, pursuant toa petition filed under 37 C.F.R. 153(c)(2)(i) filed Mar. 19, 1998.

FIELD OF INVENTION

This invention relates to compounds useful in elevating high densitylipoprotein, the “good” cholesterol. Compounds of this inventionincrease plasma levels of HDL in a cholesterol fed rat model and as suchthese compounds may be useful for treating diseases such asatherosclerosis.

BACKGROUND OF THE INVENTION

It is widely beleived that HDL is a “protective” lipoprotein [GloriaLena Vega and Scott Grundy, Current Opinion in Lipidology, 7, 209-216(1996)] and that increasing plasma levels of HDL may offer a directprotection against the development of atherosclerosis. Numerous studieshave demonstrated that both the risk of coronary heart disease (CHD) inhumans and the severity of experimental atherosclerosis in animals areinversely correlated with serum HDL cholesterol (HDL-C) concentrations(Russ et al., Am. J. Med., 11 (1951) 480-493; Gofman et al, Circulation,34 (1966) 679-697; Miller and Miller, Lancet, 1 (1975) 16-19; Gordon etal., Circulation, 79 (1989) 8-15; Stampfer et al., N. Engl. J. Med., 325(1991) 373-381; Badimon et al., Lab. Invest., 60 (1989) 455-461).Atherosclerosis is the process of accumulation of cholesterol within thearterial wall which results in the occlusion, or stenosis, of coronaryand cerebral arterial vessels and subsequent myocardial infarction andstroke. Angiographical studies have shown that elevated levels of someHDL particles in humans appears to be correlated to a decreased numberof sites of stenosis in the coronary arteries of humans (Miller et al.,Br. Med. J., 282 (1981) 1741-1744).

There are several mechanisms by which HDL may protect against theprogression of atherosclerosis. Studies in vitro have shown that HDL iscapable of removing cholesterol from cells (Picardo et al.,Arteriosclerosis, 6 (1986) 434-441). Data of this nature suggest thatone antiatherogenic property of HDL may lie in its ability to depletetissues of excess free cholesterol and eventually lead to the deliveryof this cholesterol to the liver (Glomset, J. Lipid Res., 9 (1968)155-167). This has been supported by experiments showing efficienttransfer of cholesterol from HDL to the liver (Glass et al.,Circulation, 66 (Suppl. II) (1982) 102; MacKinnon et al., J. Biol.Chem., 261 (1986) 2548-2552). In addition, HDL may serve as a reservoirin the circulation for apoproteins necessary for the rapid metabolism oftriglyceride-rich lipoproteins (Grow and Fried, J. Biol. Chem., 253(1978) 8034-8041; Lagocki and Scanu, J. Biol. Chem., 255 (1980)3701-3706; Schaefer et al., J. Lipid Res., 23 (1982) 1259-1273).Accordingly, agents which increase HDL cholesterol concentrations areuseful as anti-atherosclerotic agents, particularly in the treatment ofdyslipoproteinemias and coronary artery disease.

Takagi et al., U.S. Pat. No. 5,608,109, discloses agricultural andhorticultural insecticidal compounds according to formula A below whereAr and R² is optionally substituted phenyl, R¹ and R³ are independentlyhydrogen, alkyl, alkenyl or alkynyl, and R⁴ and R⁵ are independentlyhydrogen or alkyl.

BRIEF DESCRIPTION OF THE INVENTION

The compounds of this invention which elevate plasma levels of HDLcholesterol have the general structure A

wherein:

R¹, R², and R³ are independently hydrogen, C₁-C₆ alkyl, phenyl or—(CH₂)₁₋₆ phenyl where phenyl is optionally substituted by halogen,cyano, nitro, C₁-C₆ alkyl, C₁-C₆ alkoxy, trifluoromethyl, C₁-C₆alkoxycarbonyl, —CO₂H or OH;

R⁴ and R⁵ are independently hydrogen, C₁-C₁₀ alkyl, C₃-C₈ cycloalkyl,—(CH₂)₀₋₆Ar¹ where Ar¹ is phenyl, naphthyl, furanyl, pyridinyl or thenyland Ar¹ can be optionally substituted by halogen, cyano, nitro, C₁-C₆alkyl, phenyl, C₁-C₆ alkoxy, phenoxy, trifluoromethyl, C₁-C₆alkoxycarbonyl, —CO₂H or OH, or R⁴ and R⁵ together with the nitrogen towhich R⁴ and R⁵ are attached form a ring containing 4-7 carbon atoms;

and Ar is phenyl, naphthyl, furanyl, pyridinyl or thienyl which may beoptionally substituted by halogen, cyano, nitro, C₁-C₆ alkyl, C₃-C₆cycloalkyl, phenyl, C₁-C₆ alkoxy, phenoxy, trifluoromethyl, C₁-C₆alkoxycarbonyl, —CO₂H or OH; with the proviso that Ar and R² cannotsimultaneously be optionally substituted phenyl when the R¹ and R³ areindependently hydrogen or alkyl.

The compounds are tested in vivo in rats fed cholesterol-augmentedrodent chow for 8 days according to the test protocol and blood from therats analyzed for HDL cholesterol.

DETAILED DESCRIPTION OF THE INVENTION

The compounds of this invention are prepared by reacting4-oxo-4-arylbutyric acid amides with an appropriately substitutedthiosemicarbazide according to Scheme I. The intermediate4-oxo-4-arylbutyric acid amides are conveniently prepared by the routesshown in Scheme II by reacting an amine of the formula HNR⁴R⁵ witheither a 4-aryl-4-oxobutyric acid or a γ-aryl-γ-butyrolactone. Specificexamples are given in the Experimental Section.

Scheme I: Preparation of Title Compounds

Scheme II: Preparation of Intermediate 4-oxo-4-phenylbutyric Acid Amides

(1) Route A to Ketoamide 1

(2) Route B to Ketoamide 1

The following examples are included for illustrative purposes only andare not to be construed as limiting to this disclosure in any way. Thoseskilled in the art of synthetic organic chemistry may be aware of othermethods of preparing compounds of this invention. The starting materialsor intermediates are available commercially or can be prepared byfollowing standard literature procedures.

EXAMPLE 12-(4-Butylamino-4-oxo-1-phenyl-butylidene)-hydrazinothiocarboxamide

(A) 1,3-Diisopropylcarbodiimide (22.0 ml, 0.14 moles) in 200 ml ofmethylene chloride was added under nitrogen dropwise over 45 minutes toa solution of 3-benzoylpropionic acid (25.00 g, 0.14 moles),4-dimethylaminopyridine (17.16 g, 0.14 moles) and butylamine (13.9 ml,0.14 moles) in 500 ml of methylene chloride at ice bath temperature.After the addition the reaction was stirred at ice bath temperature for1 hour. The ice bath was removed and the reaction stirred for 18 hours.The solid present was removed by filtration and discarded. The filtratewas extracted with 1 N HCl, 5% NaHCO₃, dried (MgSO₄) and the solventremoved under reduced pressure to give 35.84 g of a yellow solid.Recrystallization of the solid from isopropyl alcohol gaveN-butyl-4-oxo-4-phenyl-butyramide (15.99 g, 49%) as a light yellowsolid, mp 78-80° C.

Elemental Analysis for C₁₄H₁₉NO₂

Calc'd: C, 72.07; H, 8.21; N, 6.00.

Found: C, 72.42;, H, 8.20; N, 6.07.

(B) Thiosemicarbazide (1.95 g, 21.4 mmol) was added to a solution ofN-butyl-4-oxo-4-phenyl-butyramide (5.0 g, 21.4 mmol), prepared in theprevious step, in 75 ml of methanol plus 5.8 ml of 1 N HCl plus 5.8 mlof water and the reaction stirred at room temperature for 22 hours. Thereaction was concentrated under reduced pressure at which time a solidformed. The solid was collected by filtration and dried to give 4.49 gof an off-white solid. Recrystallization of the solid from isopropylalcohol gave 3.16 g (48%) of the title compound as a white solid, mp64-68° C.

Elemental Analysis for C₁₅H₂₂N₄OS.0.8 C₃H₈O

Calc'd: C, 58.95; H, 8.07; N, 15.80.

Found: C, 58.93; H, 8.25; N, 15.45.

EXAMPLE 24-[(Aminothioxomethyl)hydrazono]-N-(1-methylethyl)-4-phenyl-butanamide

(A) In the same manner as described in step (A) of Example 1, andreplacing butylamine with isopropylamine,N-(1-methylethyl)-4-oxo-4-phenyl-butyramide (10.24 g, 33%) was obtainedas a white solid, trip 118-121° C.

Elemental Analysis for C₁₃H₁₇NO₂

Calc'd: C, 71.21; H, 7.81; N, 6.39.

Found: C, 71.14; H, 7.83; N, 6.36.

(B) Thiosemicarbazide (2.08 g, 22.8 mmol) was added to a solution ofN-(1-methylethyl)-4-oxo-4-phenyl-butyramide (5.0 g, 22.8 mmol), preparedin the previous step, in 80 ml of methanol plus 6.2 ml of 1 N HCl plus6.2 ml of water and the reaction stirred at room temperature for 2 days.An additional 1.04 g (11.4 mmol) of thiosemicarbazide was added and thereaction stirred at room temperature for 24 hours. The reaction wascooled in an ice bath and a white solid precipitated. The solid wascollected by filtration and dried. Recrystallization of the solid fromisopropyl alcohol gave the title compound (4.73 g, 53%) as a whitesolid, mp 66-71° C.

Elemental Analysis for C₁₄H₂₀N₄OS.1.6 C₃H₈O

Calc'd: C, 58.12; H, 8.51; N, 14.42.

Found: C, 57.06; H, 8.58; N, 13.80.

EXAMPLE 3 4-[(Aminothioxomethyl)-hydrazono]-4-phenylbutanamide

(A) A mixture of γ-phenyl-γ-butyrolactone (10.30 g, 63.5 mmol) and anexcess of ammonia was stirred under nitrogen and a dry ice trap for 8hours. The dry ice trap was removed and after evaporation of the ammonia11.27 g of a tan solid remained. Recrystallization of the solid fromethyl acetate-hexane gave 4-hydroxy-4-phenyl-butyramide (8.56 g, 75%) asa white solid, mp 85-87° C.

Elemental Analysis for C₁₀H₁₃NO₂

Calc'd: C, 67.02; H, 7.31; N, 7.82.

Found: C, 67.27; H, 7.25; N, 7.84.

(B) A mixture of 4-hydroxy-4-phenyl-butyramide (4.02 g, 22.4 mmol),prepared in the previous step, and pyridinium chlorochromate (7.26 g,33.7 mmol) in 500 ml of methylene chloride was stirred at roomtemperature for 2 hours. The reaction was poured onto 400 g of silicagel (230-400 mesh) and the material eluted with ethyl acetate. Isolationof the major component gave 1.92 g of a purple solid. Recrystallizationof the solid from ethyl acetate gave 4-oxo-4-phenyl-butyramide (1.24 g,31%) as a green solid, mp 122-124° C.

Elemental Analysis for C₁₀H₁₁NO₂

Calc'd: C, 67.78; H, 6.26; N, 7.90.

Found: C, 67.34; H, 6.15; N, 7.75.

(C) Thiosemicarbazide (1.38 g, 15.1 mmol) was added to a solution of4-oxo4-phenyl-butyramide (1.63 g, 9.22 mmol), prepared in the previousstep, in 50 ml of methanol plus 2.5 ml of 1 N HCl plus 2.5 ml of waterand the reaction stirred at room temperature for 28 hours. The solidformed was collected by filtration and dried to give 1.73 g of a purplesolid. Recrystallization of the solid from methanol gave the titlecompound (1.34 g, 58%) as a purple solid, mp 186-188° C.

Elemental Analysis for C₁₁H₁₄N₄OS

Calc'd: C, 52.78; H, 5.64; N, 22.38.

Found: C, 52.75; H, 5.66; N, 22.41.

EXAMPLE 4 4-[(Aminothioxomtethyl)-hydrazono]-N-benzyl-4-phenylbutanamide

(A) A solution of γ-phenyl-γ-butyrolactone (5.17 g, 31.8 mmol) andbenzylamine (3.48 ml, 31.8 mmol) in 200 ml of benzene was refluxed undera nitrogen atmosphere for 20 hours. An additional 1.75 ml (16.0 mmol) ofbenzylamine was added and the solution refluxed for 24 hours. When thereaction was partitioned with 1 N HCl a white solid precipitated. Thesolid was collected by filtration and dried to giveN-benzyl-4-hydroxy-4-phenyl-butyramide (6.12 g, 72%) as a white solid,mp 92-94° C.

Elemental Analysis for C₁₇H₁₉NO₂

Calc'd: C, 75.81; H, 7.11; N, 5.20.

Found: C, 75.64; H, 7.08; N, 5.08.

(B) A mixture of N-benzyl-4-hydroxy-4-phenyl-butyramide (5.58 g, 20.7mmol), prepared in the previous step, and pyridinium chlorochromate(6.69 g, 31.0 mmol) in 600 ml of methylene chloride was stirred at roomtemperature for 1.5 hours. The reaction was poured onto 300 g of silicagel (230-400 mesh) and the material eluted with methylene chloride-ethylacetate. Isolation of the major component gave 4.68 g (85%) of a greensolid. Recrystallization of the solid from ethyl acetate gaveN-benzyl-4-oxo-4-phenyl-butyramide as a white solid, mp 110-112° C.

Elemental Analysis for C₁₇H₁₇NO₂

Calc'd: C, 76.38; H, 6.41; N, 5.24.

Found: C, 76.33; H, 6.14; N, 5.26.

(C) Thiosemicarbazide (2.30 g, 25.2 mmol) was added to a solution ofN-benzyl-4-oxo-4-phenyl-butyramide (4.12 g, 15.4 mmol), prepared in theprevious step, in 100 ml of methanol plus 4.2 ml of 1 N HCl plus 4.2 mlof water and the reaction stirred at room temperature for 20 hours. Thereaction was cooled in an ice bath and a white solid precipitated. Thesolid was collected by filtration and dried to give 4.61 g of a whitesolid. Recrystallization of the solid from ethyl acetate-methanol gavethe title compound (2.05 g, 39%) as a white solid, mp 162-164° C.

Elemental Analysis for C₁₈H₂₀N₄OS

Calc'd: C, 63.50; H, 5.92; N, 16.46.

Found: C, 63.48; H, 5.77; N, 16.60.

EXAMPLE 5 4-[(Aminothioxomrethyl)-hydrazono]-N-methyl-4-phenylbutanamide

(A) A solution of γ-phenyl-γ-butyrolactone (5.17 g, 31.9 mmol) in 40 mlof a 2 molar solution of methylamine in THF was stirred under nitrogenat room temperature for 23 hours. The solvent was removed under reducedpressure to give 6.15 g of a yellow solid. Recrystallization of thesolid from ethyl acetate-hexane gave4-hydroxy-N-methyl-4-phenyl-butyramide (4.81 g, 78%) as an off-whitesolid, mp 67-69° C.

Elemental Analysis for C₁₁H₁₅NO₂

Calc'd: C, 68.37; H, 7.82; N, 7.25.

Found: C, 68.60; H, 7.98; N, 7.32.

(B) A mixture of 4-hydroxy-N-methyl-4-phenyl-butyramide (4.50 g, 23.3mmol), prepared in the previous step, and pyridinium chlorochromate(7.54 g, 35.0 mmol) in 200 ml of methylene chloride was stirred at roomtemperature for 2.5 hours. The reaction was poured onto 400 g of silicagel (230-400 mesh) and the material eluted with ethyl acetate-methylenechloride and then ethyl acetate. Isolation of the major component gaveN-methyl-4-oxo-4-phenyl-butyramide (3.65 g, 82%) as an off-white solid,mp 80-82° C.

Elemental Analysis for C₁₁H₁₃NO₂

Calc'd: C, 69.09; H, 6.85; N, 7.32.

Found: C, 69.08; H, 6.87; N, 7.27.

(C) Thiosemicarbazide (2.60 g, 28.5 mmol) was added to a solution ofN-methyl-4-oxo-4-phenyl-butyramide (3.33 g, 17.4 mmol), prepared in theprevious step, in 60 ml of methanol plus 4.7 ml of 1 N HCl plus 4.7 mlof water and the reaction stirred at room temperature for 22 hours. Thereaction was submerged in an ice bath and a solid precipitated. Thesolid was collected by filtration and dried to give 4.55 g of a whitesolid. The solid was triturated with water and then dried to give thetitle compound (4.10 g, 89%) as a white solid, mp 205-207° C.

Elemental Analysis for C₁₂H₁₆N₄OS

Calc'd: C, 54.52; H, 6.10; N, 21.19.

Found: C, 54.55; H, 6.02; N, 21.20.

EXAMPLE 64-[(Aminothioxomethyl)-hydrazono]-N-cyclohexyl-4-phenylbutanamide

(A) A solution of γ-phenyl-γ-butyrolactone (5.16 g, 31.8 mmol) andcyclohexylamine (7.3 ml, 63.8 mmol) in 200 ml of benzene was refluxedunder a nitrogen atmosphere for 3 days. The reaction was extracted with1 N HCl, dried (MgSO₄) and the solvent removed under reduced pressure togive 7.07 g of a brown solid. Recrystallization of the solid from ethylacetate-hexane gave N-cyclohexyl-4-hydroxy-4-phenyl-butyramide (4.22 g,51%) as a white solid, mp 91-93° C.

Elemental Analysis for C₁₆H₂₃NO₂

Calc'd: C, 73.53; H, 8.87; N, 5.36.

Found: C, 73.48; H, 9.12; N, 5.48.

(B) A mixture of N-cyclohexyl-4-hydroxy-4-phenyl-butyramide (3.98 g,15.2 mmol), prepared in the previous step, and pyridinium chlorochromate(4.94 g, 22.9 mmol) in 200 ml of methylene chloride was stirred at roomtemperature for 2.5 hours. The reaction was poured onto 400 g of silicagel (230-400 mesh) and the material eluted with methylene chloride-ethylacetate. Isolation of the major component gaveN-cyclohexyl-4-oxo4-phenyl-butyramide (3.28 g, 83%) as a light greensolid, mp 109-111° C.

Elemental Analysis for C₁₆H₂₁NO₂

Calc'd: C, 74.10; H, 8.16; N, 5.40.

Found: C, 73.64; H, 8.11; N, 5.41.

(C) Thiosemicarbazide (1.75 g, 19.2 mmol) was added to a solution ofN-cyclohexyl-4-oxo-4-phenyl-butyramide (3.30 g, 11.7 mmol), prepared inthe previous step, in 40 ml of methanol plus 3.2 ml of 1 N HCl plus 3.2ml of water and the reaction stirred at room temperature for 21 hours.The solid formed was removed by filtration and dried to give 2.69 g of awhite solid. The filtrate was concentrated under reduced pressure toremove the methanol. The residue was partitioned between methylenechloride and water. The organic layer was separated, wash ed multipletimes with water, dried (MgSO₄) and the solvent removed under reducedpressure to give 1.10 g of a white foam. The initial solid filtered fromthe reaction was dissolved in methylene chloride, washed multiple timeswith water, dried (MgSO₄) and the solvent removed under reduced pressureto give a white foam. Both materials were combined and crystallized frommethylene chloride-ethyl acetate to give the title compound (3.31 g,69%) as a white solid, mp 89-92° C.

Elemental Analysis for C₁₇H₂₄N₄OS.0.9 C₄H₈O₂

Calc'd: C, 60.09; H, 7.64; H; 13.61.

Found; C, 59.98; H, 7.67; N, 13.43.

EXAMPLE 74-[(Aminothioxomethyl)hydrazono]-N,N-dimethyl-4-phenylbutanamide

(A) A solution of γ-phenyl-γ-butyrolactone (4.84 g, 29.8 mmol) in 200 mlof a 2 molar solution of dimethylamine in THF was stirred under anitrogen atmosphere at room temperature for 2 days. The solvent wasremoved under reduced pressure to give 6.26 g of4-hydroxy-N,N-dimethyl-4-phenyl-butyramide as a light brown oil, MS[M+H]⁺ m/e 208.

Elemental Analysis for C₁₂H₁₇NO₂

Calc'd: C, 69.54; H, 8.27; N, 6.76.

Found: C, 68.13; H, 8.28; N, 6.65.

(B) In the same mariner as described in step (B) of Example6,4-oxo-N,N-dimethyl-4-phenyl-butyramide (4.08 g, 72%) was obtained asan off-white solid, mp 56-58° C.

Elemental Analysis for C₁₂H₁₅NO₂

Calc'd: C, 70.22; H, 7.37; N, 6.82.

Found; C, 70.08; H, 7.40; N, 6.95.

(C) Thiosemicarbazide (2.75 g, 30.2 mmol) was added to a solution of4-oxo-N,N-dimethyl-4-phenyl-butyramide (3.80 g, 18.5 mmol), prepared inthe previous step, in 65 ml of methanol plus 5 ml of 1 N HCl plus 5 mlof water and the reaction stirred at room temperature for 28 hours. Thesolid present was collected by filtration to give4.76 g of a whitesolid. The solid was triturated with water and then dried to give thetitle compound (4.53 g, 88%) as a white solid, mp 173-175° C.

Elemental Analysis for C₁₃H₁₈N₄OS

Calc'd: C, 56.09; H, 6.52; N, 20.13.

Found: C, 55.64; H, 6.37; N, 19.78.

EXAMPLE 81-[4-[(Aminothioxomethyl)hydrazono]-1-oxo-4-phenylbutyl]piperidine

(A) In the same manner as described in step (A) of Example 6, andreplacing cyclohexylamine with piperidine,4-hydroxy-4-phenyl-1-piperidin-1-yl-butan-1-one (4.86 g, 62%) wasobtained as an off-white solid, mp 42-44° C.

Elemental Analysis for C₁₅H₂₁NO₂

Calc'd: C, 72.84; H, 8.56; N, 5.66.

Found: C, 72.83; H, 8.82; N, 5.63.

(B) A mixture of 4-hydroxy-4-phenyl-1-piperidin-1-yl-butan-1-one (4.00g, 16.2 mmol), prepared in the previous step, and pyridiniumchlorochromate (5.23 g, 24.3 mmol) in 150 ml of methylene chloride wasstirred at room temperature for 2.25 hours. The reaction was poured onto400 g of silica gel (230-400 mesh) and the material eluted withmethylene chloride-ethyl acetate. Isolation of the major component gave4-oxo-4-phenyl-1-piperidin-1-yl-butan-1-one (3.66 g, 92%) as a greensolid. Recrystallization of a portion of this solid from ethylacetate-hexane gave an analytically pure sample, mp 52-54° C.

Elemental Analysis for C₁₅H₁₉NO₂

Calc'd: C, 73.44; H, 7.81; N, 5.71.

Found: C, 73.55; H, 7.95; N, 5.70.

(C) In the same manner as described in step (C) of Example 7, the titlecompound (3.90 g, 91%) was obtained as a white solid, mp 181-183° C.

Elemental Analysis for C₁₆H₂₂N₄OS

Calc'd: C, 60.35; H, 6.96; N, 17.59.

Found: C, 60.14; H, 7.06; N, 17.58.

EXAMPLE 94-[(Aminothioxomethyl)-hydrazono]-N-(1,5-dimethylhexyl)-4-phenyl-butanamide

(A) A solution of γ-phenyl-γ-butyrolactone (5.02 g, 30.9 mmol) and1,5-dimethylhexylamine (10.4 ml, 61.7 mmol) in 200 ml of benzene wasrefluxed under a nitrogen atmosphere for 40 hours. An additional 10.4 ml(61.7 mmol) of 1,5-dimethylhexylamine was added and the reactionrefluxed for 26 hours. The reaction was extracted with 1 N HCl, dried(MgSO₄) and the solvent removed under reduced pressure to give to give8.26 g of a light brown solid. Recrystallization of the solid from ethylacetate-hexane gave N-(1,5-dimethyl-hexyl)-4-hydroxy-4-phenyl-butyramide(3.72 g, 41%) as a white solid, mp 72-89° C.

Elemental Analysis for C₁₈H₂₉NO₂

Calc'd: C, 74.18; H, 10.03; N, 4.81.

Found: C, 74.50; H, 10.34; N, 4.79.

(B) A mixture of N-(1,5-dimethyl-hexyl)-4-hydroxy-4-phenyl-butyramide(3.50 g, 12.0 mmol), prepared in the previous step, and pyridiniumchlorochromate (3.89 g, 18.0 mmol) in 150 ml of methylene chloride wasstirred at room temperature for 1.25 hours. The reaction was poured onto400 g of silica gel (230-400 mesh) and the material eluted withmethylene chloride-ethyl acetate. Isolation of the major component gaveN-(1,5-dimethyl-hexyl)-4-oxo-4-phenyl-butyramide (2.71 g, 78%) as alight green solid, mp 84-87° C.

Elemental Analysis for C₁₈H₂₇NO₂

Calc'd: C, 74.70; H, 9.40; N, 4.84.

Found: C, 74.38; H, 9.65; N, 4.89.

(C) Thiosemicarbazide (1.32 g, 14.5 mmol) was added to a solution ofN-(1,5-dimethyl-hexyl)-4-oxo-4-phenyl-butyramide (2.54 g, 87.9 mmol),prepared in the previous step, in 30 ml of methanol plus 2.4 ml of 1 NHCl plus 2.4 ml of water and the reaction stirred at room temperaturefor 48 hours. The reaction was concentrated under reduced pressure toremove the methanol. The residue was partitioned between methylenechloride and water. The organic layer was separated, washed multipletimes with water, dried (MgSO₄) and the solvent removed under reducedpressure to give 2.95 g of an off-white solid foam. Purification of thisfoam by chromatography on silica gel (230-400 mesh) using 3:1hexane-ethyl acetate and then 3:1 ethyl acetate-methylene chloride asthe eluents gave the title compound (2.63 g, 82%) as a white foam, mp58-65° C.

Elemental Analysis for C₁₉H₃₀N₄OS

Calc'd: C, 62.95; H, 8.34; N, 15.45.

Found: C, 62.53; H, 8.47; N, 15.35.

Pharmacology

In Vivo Assa.: Male Sprague-Dawley rats weighing 200-225 g are housedtwo per cage and fed Purina Rodent Chow Special Mix 5001-S supplementedwith 0.25% cholic acid and 1.0% cholesterol and water ad libitum for 8days. Each test substance is administered to a group of six rats fed thesame diet with the test diet mixed in as 0.005-0.1% of the total diet.Body weight and food consumption are recorded prior to dietadministration and at termination. Typical doses of the test substancesare 5-100 mg/kg/day.

At termination, blood is collected from anesthetized rats and the serumis separated by centrifugation. Total serum cholesterol is assayed usingthe Sigma Diagnostics enzymatic kit for the determination ofcholesterol, Procedure No. 352, modified for use with ninety-six wellmicrotiter plates. After reconstitution with water the reagent contains300 U/I cholesterol oxidase, 100 U/I horse radish peroxidase, 0.3mmoles/l of 4-aminoantipyrine and 30.0 mmoles/l ofp-hydroxybenzenesulfonate in a pH 6.5 buffer. In the reactioncholesterol is ;oxidized to produce hydrogen peroxide which is used toform a quinoneimine dye. The concentration of dye formed is measuredspectrophotometrically by absorbance at 490 nm after incubation at 25°C. for 30 minutes. The concentration of cholesterol was determined foreach serum sample relative to a commercial standard from Sigma.

HDL cholesterol concentrations in serum are determined by separation oflipoprotein classes by fast protein liquid chromatography (FPLC) by amodification of the method of Kieft et al., J. Lipid Res., 32 (1991)859-866. 25 μl of serum is injected onto Superose 12 and Superose 6(Pharmacia), in series, with a column buffer of 0.05 M Tris(2-amino-2-hydroxymethyl-1,3-propanediol) and 0.15 M sodium chloride ata flow rate of 0.5 ml/min. The eluted sample is mixed on line withBoehringer-Mannheim cholesterol reagent pumped at 0.2 ml/min. Thecombined eluents are mixed and incubated on line through a knitted coil(Applied Biosciences) maintained at a temperature of 45° C. The eluentis monitored by measuring absorbance at 490 nm and gives a continuousabsorbance signal proportional to the cholesterol concentration. Therelative concentration of each lipoprotein class is calculated as theper cent of total absorbance. HDL cholesterol concentration, in serum,is calculated as the per cent of total cholesterol as determined by FPLCmultiplied by the total serum cholesterol concentration.

TABLE I Cholesterol Fed Rat % Increase Example in HDL (Dose) Example 156% (100 mg/kg) Example 2 61.7% (100 mg/kg) Example 3 36.4% (50 mg/kg)Example 4 49.5% (50 mg/kg) Example 5 43.3% (100 mg/kg) Example 6 28.1%(82 mg/kg) Example 7 56.2% (50 mg/kg) Example 8 52.8% (50 mg/kg) Example9 40.4% (50 mg/kg)

Pharmaceutical Composition

Compounds of this invention may be administered neat or with apharmaceutical carrier to a patient in need thereof. The pharmaceuticalcarrier may be solid or liquid.

Applicable solid carriers can include one or more substances which mayalso act as flavoring agents, lubricants, solubilizers, suspendingagents, fillers, glidants, compression aids, binders ortablet-disintegrating agents or an encapsulating material. In powders,the carrier is a finely divided solid which is in admixture with thefinely divided active ingredient. In tablets, the active ingredient ismixed with a carrier having the necessary compression properties Insuitable proportions and compacted in the shape and size desired. Thepowders and tablets preferably contain up to 99% of the activeingredient. Suitable solid carriers include, for example, calciumphosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch,gelatin, cellulose, methyl cellulose, sodium carboxymethyl cellulose,polyvinylpyrrolidine, low melting waxes and ion exchange resins.

Liquid carriers may be used in preparing solutions, suspensions,emulsions, syrups and elixirs. The active ingredient of this inventioncan be dissolved or suspended in a pharmaceutically acceptable liquidcarrier such as water, an organic solvent, a mixture of both orpharmaceutically acceptable oils or fat. The liquid carrier can containother suitable pharmaceutical additives such a solubilizers,emulsifiers, buffers, preservatives, sweeteners, flavoring agents,suspending agents, thickening agents, colors, viscosity regulators,stabilizers or osmo-regulators. Suitable examples of liquid carriers fororal and parenteral administration include water (particularlycontaining additives as above, e.g., cellulose derivatives, preferablesodium carboxymethyl cellulose solution), alcohols (including monohydricalcohols and polyhydric alcohols, e.g., glycols) and their derivatives,and oils (e.g., fractionated coconut oil and arachis oil). Forparenteral administration the carrier can also be an oily ester such asethyl oleate and isopropyl myristate. Sterile liquid carriers are usedin sterile liquid form compositions for parenteral administration.

Liquid pharmaceutical compositions which are sterile solutions orsuspensions can be utilized by, for example, intramuscular,intraperitoneal or subcutaneous injection. Sterile solutions can also beadministered intravenously. Oral administration may be either liquid orsolid composition form.

The compounds of this invention may be administered rectally in the formof a conventional suppository. For administration by intranasal orintrabronchial inhalation or insufflation, the compounds of thisinvention may be formulated into an aqueous or partrially aqueoussolution, which can then be utilized in the form of an aerosol. Thecompounds of this invention may also be administered transdermallythrough the use of a transdermal patch containing the active compoundand a carrier that is inert to the active compound, is non-toxic to theskin, and allows delivery of the agent for systemic absorption into theblood stream via the skin. The carrier may take any number of forms suchas creams and ointments, pastes, gels, and occlusive devices. The creamsand ointments may be viscous liquid or semi-solid emulsions of eitherthe oil in water or water in oil type. Pastes comprised of absorptivepowders dispersed in petroleum or hydrophilic petroleum containing theactive ingredient may also be suitable. A variety of occlusive devicesmay be used to realease the active ingredient into the blood stream suchas a semipermeable membrane covering a reservoir containing the activeingredient with or without a carrier, or a matrix containing the activeingredient. Other occlusive devices are known in the literature.

The dosage to be used in the treatment of a specific patient sufferingfrom high density lipoprotein insufficiency must be subjectivelydetermined by the attending physician. The variables involved includethe severity of the dysfunction, and the size, age, and response patternof the patient. Treatment will generally be initiated with small dosagesless than the optimum dose of the compound. Thereafter the dosage isincreased until the optimum effect under the circumstances is reached.Precise dosages for oral or parenteral administration will be determinedby the administering physician based on experience with the individualsubject treated and standard medical principles.

Preferably the pharmaceutical composition is in unit dosage form, e.g.,as tablets or capsules. In such form, the composition is sub-divided inunit doses containing appropriate quantities of the active ingredient;the unit dosage form can be packaged compositions, for example packedpowders, vials, ampoules, prefilled syringes or sachets containingliquids. The unit dosage form can be, for example, a capsule or tabletitself, or it can be the appropriate number of any such compositions inpackage form.

What is claimed:
 1. A compound according to the formula:

wherein: R¹, R², and R³ are independently hydrogen, C₁-C₆ alkyl, phenylor —(CH₂)₁₋₆ phenyl where phenyl is optionally substituted by halogen,cyano, nitro, C₁-C₆ alkyl, C₁-C₆ alkoxy, trifluoromethyl, C₁-C₆alkoxycarbonyl, —CO₂H or OH; R⁴ and R⁵ are independently hydrogen,C₁-C₁₀ alkyl, C₃-C₈ cycloalkyl, —(CH₂)₀₋₆Ar¹ where Ar¹ is phenyl,naphthyl, furanyl, pyridinyl or thenyl and Ar¹ can be optionallysubstituted by halogen, cyano, nitro, C₁-C₆ alkyl, phenyl, C₁-C₆ alkoxy,phenoxy, trifluoromethyl, C₁-C₆ alkoxycarbonyl, —CO₂H or OH, or R⁴ andR⁵ together with the nitrogen to which R⁴ and R⁵ are attached form aring containing 4-7 carbon atoms; and Ar is phenyl, naphthyl, furanyl,pyridinyl or thienyl which may be optionally substituted by halogen,cyano, nitro, C₁-C₆ alkyl, C₃-C₆ cycloalkyl, phenyl, C₁-C₆ alkoxy,phenoxy, trifluoromethyl, C₁-C₆ alkoxycarbonyl, —CO₂H or OH; with theproviso that Ar and R² cannot simultaneously be optionally substitutedphenyl when the R¹ and R³ are independently hydrogen or alkyl.
 2. Acompound according to claim 1 which is selected from the groupconsisting of2-(4-butylamino-4-oxo-1-phenyl-butylidene)-hydrazinothiocarboxamide,4-[(aminothioxomethyl)hydrazono]-N-(1-methylethyl)-4-phenyl-butanamide,4-[(aminothioxomethyl)-hydrazono]-4-phenylbutanamide,4-[(aminothioxomethyl)-hydrazono]-N-benzyl-4-phenylbutanamide,4-[(aminothioxomethyl)-hydrazono]-N-methyl-4-phenylbutanamide,4-[(aminothioxomethyl)-hydrazono]-N-cyclohexyl-4-phenylbutanamide,4-[(aminothioxomethyl)hydrazono]-N,N-dimethyl-4-phenylbutanamide,1-[4-[(aminothioxomiethyl)hydrazono]-1-oxo-4-phenylbutyl]piperidine, and4-[(aminothioxomethyl)-hydrazono]-N-(1,5-dimethylhexyl)-4-phenyl-butanamide.3. A pharmaceutical composition for the treatment of atherosclerosiswhich comprises a pharmaceutically acceptable carrier and atherapeutically effective amount of a compound according to the formula:

wherein: R¹, R², and R³ are independently hydrogen, C₁-C₆ alkyl, phenylor —(CH₂)₁₋₆ phenyl where phenyl is optionally substituted by halogen,cyano, nitro, C₁-C₆ alkyl, C₁-C₆ alkoxy, trifluoromethyl, C₁-C₆alkoxycarbonyl, —CO₂H or OH; R⁴ and R⁵ are independently hydrogen,C₁-C₁₀ alkyl, C₃-C₈ cycloalkyl, —(CH₂)₀₋₆Ar¹ where Ar¹ is phenyl,naphthyl, furanyl, pyridinyl or thenyl and Ar¹ can be optionallysubstituted by halogen, cyano, nitro, C₁-C₆ alkyl, phenyl, C₁-C₆ alkoxy,phenoxy, trifluoromethyl, C₁-C₆ alkoxycarbonyl, —CO₂H or OH, or R⁴ andR⁵ together with the nitrogen to which R⁴ and R⁵ are attached form aring containing 4-7 carbon atoms; and Ar is phenyl, naphthyl, furanyl,pyridinyl or thienyl which may be optionally substituted by halogen,cyano, nitro, C₁-C₆ alkyl, C₃-C₆ cycloalkyl phenyl, C₁-C₆ alkoxy,phenoxy, trifluoromethyl, C₁-C₆ alkoxycarbonyl, —CO₂H or OH.
 4. Apharmaceutical composition according to claim 3 wherein the compoundused is selected from the group consisting of:2-(4-butylamino-4-oxo-1-phenyl-butylidene)-hydrazinothiocarboxamide,4-[(aminothioxomethyl)hydrazono]-N-(1-methylethyl)-4-phenyl-butanamide,4-[(amninothioxomethyl)-hydrazono]-4-phenylbutanamide,4-[(aminothioxomethyl)-hydrazono]-N-benzyl-4-phenylbutanamide,4-[(aminothioxomethyl)-hydrazono]-N-methyl-4-phenylbutanamide,4-[(aminothioxomethyl)-hydrazono]-N-cyclohexyl-4-phenylbutanamide,4-[(aminothioxomethyl)hydrazono]-N,N-dimethyl-4-phenylbutanamide,1-[4-[(aminothioxomnethyl)hydrazono]-1-oxo4-phenylbutyl]piperidine, and4-[(aminothioxomethyl)-hydrazono]-N-(1,5-dimethylhexyl)-4-phenyl-butanamide.